Data Visualization with Python and JavaScript, 2nd Edition

Chapter 2. A Language-Learning Bridge Between Python and JavaScript

Probably the most ambitious aspect of this book is that it deals with two programming languages. Moreover, it only requires that you are competent in one of these languages. This is only possible because Python and JavaScript (JS) are fairly simple languages with much in common. The aim of this chapter is to draw out those commonalities and use them to make a learning bridge between the two languages such that core skills acquired in one can easily be applied to the other.

After showing the key similarities and differences between the two languages, I’ll show how to set up a learning environment for Python and JS. The bulk of the chapter will then deal with core syntactical and conceptual differences, followed by a selection of patterns and idioms that I use often while doing data visualization work.

Similarities and Differences

Syntax differences aside, Python and JavaScript actually have a lot in common. After a short while, switching between them can be almost seamless.¹ Let’s compare the two from a data visualizer’s perspective:

These are the chief similarities:

• They both work without needing a compilation step (i.e., they are interpreted).

• You can use both with an interactive interpreter, which means you can type in lines of code and see the results right away.

• Both have garbage collection, which means they manage program memory automatically.

• Neither language has header files, package boilerplate, ...